TODO

   1 - port changes from recent versions of lttng kernel (in progress by pmf)
   2 - make cli interface for changing subbuffer size and number (in progress by Douglas Santos)
   3 - performance testing tool (in progress by Rafik Fahem)
   4 - add buffering for receiving side in libustcomm
   5 - improve support for combined kernel/userspace tracing
   6 - make a trace testing script (that can assert whether a trace contains certain events)
   7 - make web site
   8 - make sure the proper structures are cacheline aligned, and test performance, including multi-threaded
   9 - use signal safe snprintf
  10 - test with smaller subbuffer sizes
  11 - fix header/lib priority problem at compilation
  12 - fix FIXME's in the code
  13 - make a system (signal-based?) that allow the listener thread to not be started initially
  14 - make cli interface for flight recorder
  15 - save_registers: save them only when the marker is active (complicated because we need to know their value at the address that is put in struct marker)
  16 - make streaming work
  17 - ustd should work as a pool of threads
  18 - support multiple simultaneous traces
  19 - update viewer to support alignment of ust traces taken on different systems